The sponges have no stomach or mouth or other organs in their body. A lot of them live in the ocean, others live in fresh waters. This invertebrate takes waters in through their small holes. The sponges gets their food by trapping bits of food in the water using their tissues.

Sponges

The sponges have no stomach or mouth or other organs in their body. A lot of them live in the ocean, others live in fresh waters. This invertebrate takes waters in through their small holes. The sponges gets their food by trapping bits of food in the water using their tissues.

They cannot move. Most of the sponges smell so bad, others taste so bad which prevent them from being eaten by other animals.

Coelenterates

This animals are often characterized of having stinging cells and having a bag like body. Examples of this group are sea anemone, jelly fish and corals.

They have tentacles that grows on its openings. Their tentacles was covered by stinging cells. The anemone can move within the surroundings by drifting in the water of through rolling their bodies. Other anemones sometimes takes a ride with other animals.

The corals cannot move, they only stay in one place and build their homes from the nutrients or minerals they took from water.

The Jelly Fish also lives in the ocean. Through sucking water in with their mouths and squeezing the water out, jelly fish swims in water.

There are three invertebrates in the worm family, the Flatworm, the Round worm and the Segment or Sectioned worm. This worms have different body plans.

Flatworm is characterized by having a flat body and one body opening. Most of them are parasites which relies and live within the body of another organism. They take in the nutrients from the body of the organism in which they live. They have no capabilities to digest food and relies only to the food digested by the home organism they live in.

One of their kind, the Tapeworm can grow up to 30 meters long. Another Flatworm the Planarians can grow only for less than one centimeters long. They can regenerate or grow new body part, after losing other part.

The Roundworm is characterized by having a body that looks like a tube and with an opening in both ends. They have the capability to digest food. The food enters in one end and the waste goes out to another end. They live in soil and water. Most of them eats the dead animals or plants

The Segment worm is characterized by having many special organs in each of its segments. Segment worms also has two body openings. They it the soils and crawls unto it. An example of this is an Earthworm who has several hearts through its body.

The organs in the body of the Earthworm digest bits of dead animals and plants in the soil. The soils that had eaten passes through the other end of its body.

Echinoderms

Echinoderms have tough skins and spines. The Echinoderms live on the ocean. Belong to this group are Sea Urchins, Sea Stars and the Sand Dollars. This animals have many tube feet. The tube feet was use to walk in the ocean floor. They also used this tube to catch their food.

Mollusk are invertebrates with a soft body. They live in different places, some in the oceans, some in fresh water, and some on land. Mollusk have organs that digest food and pumps blood. They also have organs that takes the oxygen from water. They make their body shells from the minerals they take from the water.

Mollusk that have shells usually have strong and large foot. The mouth of a mollusk is located on its foot. Another kind kind of mollusk are the octopus and squid, They both have no shells. They swim in the water. They have organ called a Siphon. Siphon causes jet action. The Octopus and Squid sucks waters in and forces it out quickly through the Siphon which allows their body to move quickly.

They can change color and shoot out black liquid which allows them to keep away or to hide from their enemies. They uses their tentacles to catch their food.